COMSOL 4.2 Release Highlights

Released May 18, 2011

COMSOL
Multiphysics 4.2 represents a significant expansion of the software’s
applications, features, and functionality. Version 4.2 empowers current
users to do more with their simulation environments, while new
industries will now be able to leverage the innovation of multiphysics
simulation. With this release, COMSOL continues to deliver on its
promise to supply the science and engineering markets with the
state-of-the-art simulation products for an expanding set of
applications.

Geomechanics Module

The Geomechanics Module is a specialized add-on to the Structural
Mechanics Module for simulation of geotechnical applications such as
tunnels, excavations, slope stability, and retaining structures. The
Module features tailored interfaces to study plasticity, deformation,
and failure of soils and rocks, as well as their interaction with
concrete and human-made structures.

Simulations of a retaining wall (left), a tunnel excavation (middle)
and a flexible footing (right) using the Geomechanics Module

LiveLink™ for AutoCAD®

With the new LiveLink for AutoCAD interface you can transfer a 3D
geometry from AutoCAD to COMSOL Multiphysics. The synchronized geometry
in the COMSOL model stays associative with the geometry in AutoCAD. This
means that settings applied to the geometry, like physics or mesh
settings, are retained after subsequent synchronizations. The LiveLink
interface is also bidirectional to allow you to initiate a change of the
AutoCAD geometry from the COMSOL model.

Electrodeposition Module

The Electrodeposition Module brings the power of COMSOL Multiphysics
to electrochemical processes for such diverse applications as chrome
plating in automotive industry, e-coating, electro-coloring, decorative
electroplating, and electrodeposition for PCB manufacturing.

Simulations of an electrowetting lens (left) and
molecular flow (right) using the Microfluidics Module.

LiveLink™ for SpaceClaim®

The new LiveLink for SpaceClaim brings you the fusion of direct
modeling and multiphysics simulation in a tightly integrated
environment, enabling optimal designs and collaboration across CAD and
CAE teams

One-Window Interface

LiveLink for SolidWorks has been extended with a One Window Interface
where a SolidWorks user can stay inside of the SolidWorks environment
and work synchronously with COMSOL Multiphysics.

Mesh and Geometry

Coordinate-Based Selections

When analyzing multiple slightly modified versions of the same part,
Coordinate-Based Selections provide a quick way of repeating a
simulation without having to change any material settings, boundary
conditions or mesh parameters. Coordinate-Based Selections can be parameterized
in the same way as geometry objects.

In the picture, a
bracketassembly is analyzed:first with eight mountingbolts and then
with twelve mounting bolts. A coordinate-box selection is used to select
all objects within the box and to apply fixed constraints to the eight
mounting bolts. In the next step, four mounting bolts have been added
and the coordinate-box selection automatically applies the fixed
constraints.

Cap Faces

The Cap Faces geometry operation makes it easy to cover the ends of
fluid channels and subsequently mesh the interior of imported CAD parts.
Just select the edges that trace out the surface to be formed. This
operation makes for a quicker and easier transition from a purely
mechanical model to a fluid or fluid-structure interaction (FSI) model.
This feature requires the CAD Import Module or one of the CAD LiveLink products.

Meshing using Virtual Geometry Operations

New Virtual Geometry tools allow for modification of CAD models
without changing the underlying surface curvature. By applying the Form
Composite Faces operation, a much more useful mesh is produced that
accurately represents the surface shape without adding too many
elements. COMSOL Multiphysics is furthermore capable of using
higher-order elements to represent curved surfaces during analysis.

Parametric Surfaces

The new Parametric Surfaces feature allows for creation of surfaces
based on analytical expressions or look-up table data. You can tune the
resolution of the underlying NURBS surface to enable a more detailed
surface representation and finer mesh when called upon.

The picture shows a
flow simulation where imported elevation data was used to represent the
gap of a rock fracture.

Studies and Solvers

Time-Dependent Adaptive Mesh Refinement

Two-phase flow simulations can now be solved more efficiently with a
new time-dependent adaptive mesh refinement algorithm. In addition to
two-phase flow, time-dependent adaptive meshing is available for any
time-dependent simulations.

The picture shows an
inkjet model from the Model Library of the Microfluidics Module (also
available in the CFD Module). The adaptive mesher automatically
identifies the need for a denser mesh at the phase boundary between air
and ink and dynamically updates throughout the transient simulation.

Automatic Remeshing for Moving Meshes

For a simulation that includes a moving mesh, a new automatic
remeshing feature makes more extreme deformation states possible. When
the mesh is deformed beyond a user-defined mesh quality threshold, the
automatic remeshing activates, and the simulation is automatically
continued, starting from the new mesh.

Physics Selection in Study Steps

A new Physics Selection utility makes it easy to activate or
deactivate select Physics Interfaces during the modeling process. You
can use this to control which physics should be considered for a
particular study step.

Convergence Plot for Solvers

Convergence plots are now available for monitoring convergence of
nonlinear, iterative, and time-dependent solvers. For nonlinear
simulations, separate convergence plots show the convergence of the
nonlinear iterations and the core linear algebra solver iterations.

Fast Parallelized Assembly and Solvers

The COMSOL Multiphysics direct solvers have been multicore and
cluster-enabled for several years. With Version 4.2, the multiphysics
assembly algorithms and iterative solvers are also parallelized which
brings faster and more memory efficient computations for a wide range of
applications on virtually any type of computer platform from laptop to
cluster.

The picture shows the squeezed elements
generated by a moving boundary and the resulting elements directly after
an automatic remesh. The model is available in the Electrodeposition
Module Model Library.

Results and Visualization

Report Generator

The new Report Generator generates HTML reports of models. The Report
Generator is an integrated part of the model, and you can add several
reports to a model. A report includes a table of contents with clickable
links to the contents below. The Report Generator uses a built-in Style
Sheet, but you can use a custom Style Sheet to change the appearance of
the report in a web browser.

Nyquist Plots

A Nyquist plot shows the magnitude and phase of a frequency-response
simulation result. This type of plot shows the magnitude as the distance
from the origin and the phase as the angle using a curve with the
frequency as the parameter. Nyquist plots have important applications
for users of the AC/DC, RF, Structural Mechanics, Acoustics, MEMS, and
Batteries & Fuel Cells Modules.

Streamline Ribbon Plot

Streamlines can now be visualized using ribbon plots where the width
and color of the ribbons can be controlled by an arbitrary expression.
The pictures show two different ribbon plots for a turbulent flow
simulation.

Histogram Plots

Histogram plots, available in Results, is used to show the
distribution of data throughout volumes, surfaces, edges, or points in a
model. You can control bins based on number of bins or data limits.
Plots can be continuous or discrete and data normalization options
include Neutral, Peak, or Integral.

RMS and Variance of Data Series

For Derived Values, you can apply an operation such as the integral
or maximum of the averaged quantity for the data series. For example,
you can immediately display the integral or maximum of the averaged
quantity for each step in the data series. Additional operations made
available with Version 4.2 are RMS (the root mean square or quadratic
mean) and Variance.

Default Plots

In the Results node of the Model Builder tree, new default plots are
now adapted to the physics in the model with descriptive names of the
created plot groups.

Mathematical Interfaces

New PDE and ODE Interfaces

The interfaces for partial differential equations (PDEs) are extended
with an additional set of templates for equations defined on surfaces
and edges. Applications include using the new Coefficient Form Boundary
PDE interface for surface diffusion, accumulation of material on
boundaries, and equation-based shell modeling for any type of physics.

A new set of interfaces are available for spatially distributed
ordinary differential equations (ODEs) and differential algebraic
equations (DAEs). Applications include material-memory simulations, such
as bioheating damage computations or material creep, where the material
state is represented with a unique state-variable at each point in the
computational volume.

The Classical PDE interfaces now include templates for the Heat
Equation and the Convection-Diffusion Equation.

All PDE, ODE, and DAE interface templates can be used freely in
multiphysics combinations with any application-specific modules.

Material Library Tools

Material Rendering

Materials are now rendered using color, texture, and reflectance.
Gold, copper, air, water, concrete, and some other common materials have
their own specific material appearance properties. A material’s
appearance can be customized and includes separate settings for
specular, diffusive, and ambient colors as well as texture noise levels.
To enable texture rendering, set the Visualization preferences to be
Optimized for Quality.

General COMSOL Desktop Functionality

Drag-and-Drop in the Model Builder Tree

Drag-and-drop is now supported in the Model Builder tree. Using this
feature, you can change the order of existing nodes or copy or duplicate
nodes.

Updated Progress and Log Windows

Progress and Log information is now available in separate windows.
The Progress window features Auto-clearing. The Log window supports
Clear and Lock as well as Resume scroll. There is now an extra log
divider with model name when opening a new model.

Small-signal Analysis

Small-signal analysis is now generally available for all modules,
including the AC/DC Module.

The picture shows a typical
application: an inductor with a nonlinear magnetic core and an
inductance that changes with increased current. The variable inductance
is also known as the small-signal, or differential, inductance.

Lumped Ports for AC/DC Analysis

A Lumped Port boundary feature is now available in the Magnetic
Fields interface and in the Magnetic and Electric Fields interface. This
feature is used for easier excitation of coils and other conducting
structures. It also gives access to S-parameters.

Acoustic-Piezoelectric Interaction

A new multiphysics interface for Acoustic-Piezoelectric coupling
makes piezo-acoustics functionality easier to use. Analyses are
available for frequency domain and time domain studies and combine
features from the Pressure Acoustics, Solid Mechanics, Electrostatics,
and Piezoelectric Devices interfaces.

Acoustic-Shell Interaction

A new multiphysics interface for Acoustic-Shell Interaction enables
modeling of vibrating thin elastic structures and their induced sound
pressure field. The coupling is bidirectional and is available for
frequency domain and the time domain studies in 3D. The Acoustic-Shell
Interaction interfaces combine features from the Pressure Acoustics and
Shell interfaces of the Acoustics Module and the Structural Mechanics
Module, respectively.

Elastic and Poroelastic Waves

The Acoustics Module features two new interfaces for waves in solid
and porous media. The Elastic Waves interface, for general elastic
solids, can be combined with a new Poroelastic Waves interface for
frequency-domain analysis of poroelastic wave propagation.

Thermoacoustics

The Acoustics Module features new dedicated modeling tools for
thermoviscous acoustics that enable highly accurate simulation of
miniaturized speakers and microphones in handheld devices.

The need for thermoacoustics emerges whenever the dimensions of an
acoustic device become small compared to the viscous and thermal
boundary layers.

The picture to the right shows an acoustic coupler with a damped
Helmholtz resonator. The model includes thermal conduction and viscous losses.

The picture to the left shows the thermoacoustic wave-field
in a shallow uniform waveguide with results matched to an analytical solution.

Batteries & Fuel Cells Module

Batteries & Fuel Cells Module

The Batteries & Fuel Cells Module features a new AC Impedance Study
type for simulating Electrochemical Impedance Spectroscopy (EIS). A new
Surface Reactions interface enables modeling of surface reactions on
boundary surfaces. A Material Library comes with common battery
electrode materials and electrolytes.

The picture shows the Temperature field in the
cooling channels and the batteries in a battery pack for automotive
applications. The model includes a high-fidelity electrochemical model
of the batteries coupled to a thermal analysis for the batteries and the
components in the battery pack, and the fluid flow in the cooling
channels.

High-Mach Number Fluid Flow

The new High-Mach Number Fluid Flow interface applies when the flow
velocity is large enough to introduce significant changes in the density
and temperature of the fluid; the thermodynamic properties of the fluid
are coupled. Appreciable changes in the fluid properties are encountered
as the flow velocity approaches, or exceeds, the speed sound. As a rule
of thumb, velocities greater than 0.3 times the speed of sound are
considered to be high Mach number flows. Important applications include:
nozzles, pipe networks, valves, and aerodynamic phenomena.

The picture shows a
benchmark model for turbulent compressible flow in a two-dimensional
converging-diverging diffuser (Sajben diffuser). The flow enters the
diffuser at a velocity of Ma = 0.46, accelerates through the converging
part, and reaches supersonic conditions at the throat of the diffuser.
The supersonic flow is terminated with a shock in the diverging part,
after which the flow is subsonically decelerated.

Chemical Reaction Engineering Module

Reacting Flow

A new physics interface for Reacting Flow, Diluted Species, makes
coupled mass and momentum transport in free and porous media available
from one single user interface. A similar physics interface for
Concentrated Species is also available. The model coupling for the
velocity field and mixture density is set up automatically. In addition,
the effective transport coefficients in a porous matrix domain can be
derived based on the corresponding values in for a non-porous domain.

Infinite Elements for Diffusion

COMSOL Multiphysics Version 4.2 introduces a new way of defining
Infinite Elements for simulation of unbounded regions. Since different
physics can share the same Infinite Elements, you can now define
Infinite Elements in the Model Definitions node, eliminating redundant
action on each Physics Interface.

The interface for Transport of Diluted Species now provides Infinite
Elements for diffusion simulations using the new mechanism. The picture
shows the new Model Builder tree node.

Parameter Estimation in Chemical Reaction Models

By combining the Chemical Reaction Engineering with the Optimization
Modules, you can use a new Parameter Estimation feature for predefined
reactor types in the Reaction Engineering interface.

Surface Reactions

A new Surface Reactions interface is used for reactions involving
surface adsorbed species and species in the bulk of a reacting surface.
The interface is applied to the boundary of a model and is coupled to a
mass transport interface in the adjacent bulk domain. The Surface
Reactions interface can be used together with the Chemical Species
Transport, Reacting Flow, and the Electrochemistry interfaces.
Predefined expressions for the growth velocity of the reacting surface
makes it easy to set up models with moving boundaries.

The picture shows a tutorial model for finding
the Arrhenius parameters of a first-order reaction where Benzene
diazonium chloride decomposes to benzene, chloride, and nitrogen.

Heat Transfer Module

Thermal Wall Functions with Radiation

Thermal wall functions with turbulence now support the
Surface-to-Surface Radiation and Highly Conductive Layer features. This
enables very sophisticated thermal simulations: including any
combination of turbulent flow, heat transfer in fluids, heat transfer in
solids, heat radiation, and thin thermally high-conducting layers such
as metal sheets.

Fan and Grill Boundary Conditions

Electronic cooling simulations are made easier by the new Fan and
Grill boundary conditions. A new Fan boundary condition is also
available on interior boundaries, called a slit condition. Fan curves
can be entered, or loaded from file, in table format for use at inlets
in flow models.

Thermal Light Color Table

A new default Color Table (color scale) named Thermal Light is
optimized for visualization of heat transfer simulations. The color
range is truncated at the lower end and eliminates the darkest shades of
red.

Plasma Module

Surface Reactions for Plasmas

New tools are available for modeling surface reactions and species.

The picture shows the accumulated height of Silicon deposited on the
wafer surface as a function of time. The model verifies that the total
mass in the system is conserved. The principle can be applied to study
processes like chemical vapor deposition (CVD) and plasma enhanced vapor
deposition (PECVD).

RF Module

Far-Field in a Medium (RF) and New Models

For computing radiation patterns from antennas and radiating
components, far-field evaluation is an essential tool. The far-field
feature has been extended and now supports computing the far field in a
medium other than vacuum. It has changed from being a boundary feature
to being a domain feature with a domain selection and a boundary
selection.

The picture to the
right shows a model of a plane wave incident on a wire grating on a
dielectric substrate. Coefficients for refraction, specular reflection,
and first order diffraction are all computed as functions of the angle
of incidence. This analysis is made possible by a new port boundary
condition for Floquet-type periodic boundary conditions.

The picture to the left shows a
new tutorial models for impedance matching of a lossy anisotropic
ferrite 3-port circulator.

New Structural Mechanics Features

Piezoelectric PMLs

New Piezoelectric Perfectly Matched Layers (PMLs) are capable of
simultaneously absorbing the elastic and electric components of an
outwards traveling piezoelastic wave. This feature is important for
modeling piezo transducers and acoustic wave filters such as BAW and
SAW. The functionality is available in the Structural Mechanics Module,
MEMS Module, and Acoustics Module.

Infinite Elements for Solid Mechanics

For Solid Mechanics, certain modeling tasks require the computation
of stress and strain for a large slab of material. For practical reasons
such models are artificially truncated close to a region of interest and
the analyst then faces the problem of what boundary conditions to apply
to the truncated domain boundaries. Modeling with Infinite Elements
avoids this problem entirely by automatically scaling the computational
domain to infinity. The Structural Mechanics and the MEMS Modules offer
Infinite Elements as a new feature under the Model Definitions node in
the Model Builder tree.

Springs and Dampers

For simulating non-rigid boundaries, new boundary conditions for
springs and dampers have been added for points, edges, boundaries, and
domains. This functionality is available for all interfaces in the
Structural Mechanics Module and for the Solid Mechanics interfaces in
the Acoustics and MEMS Modules. Similarly, a new Thin Elastic Layers
boundary condition is available on interior boundaries and between pairs
in assemblies.

Beam Cross-Section Library withCommon Sections

Prestressed Analysis

The Structural Mechanics, MEMS , and Acoustics Modules
offer new powerful and easy-to use tools for prestressed analysis of
eigenmode and frequency-response. Structures modeled with the Solid
Mechanics interface can be prestressed by mechanical, thermal, or
arbitrary multiphysics-based loads.

The picture shows one of the
tutorial models in the Model Library of the Structural Mechanics Module,
which compares the frequency response of an unloaded case with that of a
prestressed case.

Added Mass

Added mass can now be specified for edges, boundaries, and domains
for all interfaces in the Structural Mechanics Module and for the Solid
Mechanics interfaces in the Acoustics and MEMS Modules. Important
applications are: modeling non-structural added mass for a vibrating
structure immersed in a fluid, adding mass from thin layers that are not
contributing to the structure's stiffness, correcting for mass changes
due to CAD defeaturing, or including mass from components that are not
represented by any geometry in the model.

Subsurface Flow Module

The Subsurface Flow Module (previously named the Earth Science
Module) benefits from many of the new features of Version 4.2.

Combining the new Geomechanics Module with the Subsurface Flow Module
enables new geotechnical multiphysics combinations such as elastoplastic
soil models with poroelasticity as well as rock material models with
solute transport.

Thin Diffusion Barrier Boundary Condition

A new Thin Diffusion Barrier boundary condition for interior
boundaries in the Solute Transport interface enables modeling of thin
layers of much thinner diffusion coefficient than that of adjacent
domains.